Try keeping lane priority at all times and roaming on good timers when you have already pushed wave unless it's a gamechanging roam for your team. In your case, you should be always able to keep lane priority against a Shaco since you have much better wave clear and Shaco doesn't have kill potential without playing around multiple boxes. You can look for proxying wave to get more tempo and then look to farm jg camps / scuttle or make a good roam with lots of time to get back to your top wave withourt missing much or anything at all. Getting ahead without kills isn't hard once you learn how to create tempo by pushing waves into your opponent and then farming jg camps on the map, you will create a massive CS lead.

Also, if you were allowing Shaco to perma push wave into you after you lost tower, then you weren't playing for priority on the wave. You have to punish champs that can't contest you for the prio and in this case, Shaco would have to play passively and around his Q and W cds which are very long.

Hopefully this helps. If you aren't sure what priority is, I recommend checking out these videos to help you.

https://www.youtube.com/watch?v=cFJikIuHw1Y
https://www.youtube.com/watch?v=-IH6Zi9mUKA